If it only blows out the defrost, you need to replace the mode actuator. It is located on the left side of the hvac case near the gas pedal. It is held on with two 5.5mm screws. The top and bottom actuators only control tempature.

Okay I misunderstood what you were saying. If you move the temperature controls for each side, which side will not change the passenger or drivers side?Does the drivers side stay cold no matter where the setting is?

I want you to try something to see if this changes anything. The drivers temp actuator is located on the bottom of the hvac case just above the rh side of the trans tunnel. Unplug it and see if the passenger temp and mode position starts working correctly. let me know what you find

THe only way to access the passenger temp actuator is to remove the dash. It is located on the top of the hvac case in the middle of the dash area. You can remove the upper dash panel, but the defrost and vent ducts will be in the way of getting to it.